OnePlus has reportedly started soak testing the latest Android 6.0.1 Marshmallow update for Oxygen OS on OnePlus 2 devices. OxygenOS is a customised version of Android OS developed by the Chinese smartphone manufacturer for the overseas market.

The version being released to select users is Oxygen 3.0 and includes the March security update by Google. This a follow-up to the Oxygen 2.2.1 version which was released to the public only last week and brought about changes like RAW support for camera, Bluetooth compatibility improvement, Ultra SIM compatibility improvement, fix for image corruption issue and more.

The screenshots show the customizations brought about by OnePlus to the latest OS updateAndroid Police

While the version does read as Android's 6.0.1 update, the screenshots revealed by a user show that it is quite different from what we seen so far for a Marshmallow interface on other phones. Little tweaks by OnePlus have been baked into its ROM with new wallpapers, a slider for alerts, and customisation for the home screen.

Soak test typically means that an update is close to its rolling out stage but the waiting period is mainly dependent on whether any major bugs are found, which will likely determine how quickly the update moves from testing to rollout. Compared to other manufacturers, OnePlus has been slow in bringing the Marshmallow update with not even one of its handsets getting the update till now.

The latest tests, however, indicate that OnePlus 2 in fact will be the first to get the over-the-air update for the Marshmallow when it is released which may be followed by the company's newest model OnePlus X and finally by its oldest model One Plus One.